- SHORE A
- ±5 pts against the specified hardness
- TENSILE
- Per compound datasheet, ASTM D412
Oil Seals · Made to order
Silicone Rotary Shaft Seals — High-Temperature, Low-Speed Service
Silicone rotary shaft seals for high-temperature service — −60 to +220 °C, the widest range we mix. Made to DIN 3760 and ISO 6194 sizes. Specify silicone only where temperature rules out nitrile and FKM, and the shaft turns slowly: silicone abrades, so lip life is shorter. Not for mineral oil.
- HARDNESS
- 60–80 Shore A typical for a silicone lip
- TEMPERATURE
- −60 to +220 °C
- SIZE
- Shaft Ø × bore Ø × width, DIN 3760 / ISO 6194
- TYPE
- Type A plain lip or Type AS with dust lip
- MAX SHAFT SPEED
- Stated per application
- MADE TO ORDER
- ISO 9001:2015
- 09111526A
Product gallery
Visual Reference
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Cross section viewSection through lip, case and spring — on request
- Shaft diameter
- The first of the three ordering numbers
- Shaft speed
- Surface speed at the lip
- Duty cycle
- Continuous or intermittent — intermittent running extends a silicone lip considerably
- Shaft surface finish
- Matters more here than on any other compound, because the lip has least abrasion resistance to spare
- Peak temperature
- Stated separately from continuous — usually the reason silicone is being considered
Section drawing available on request. Send shaft diameter, housing bore and width, plus the shaft speed, the duty cycle and both temperatures — and we will confirm whether silicone is the right choice before quoting it.
Technical specifications
Engineering Data
- Product Family
- Oil Seals
- Material
- Silicone (VMQ)
- Hardness (Shore A)
- 60–80 Shore A typical for a lip
- Tensile Strength
- Per compound datasheet, ASTM D412
- Elongation at Break
- Per compound datasheet, ASTM D412
- Operating Temperature
- −60 to +220 °C
- Compression Set
- ASTM D395 Method B
- Density
- Per compound datasheet
- Colour Options
- Silicone is readily supplied in light colours — useful where contamination must be visible, or to distinguish it from nitrile in service
- Lead Time
- Confirmed with the quotation, from approved drawing and approved sample
- Abrasion resistance
- Low
- Max shaft speed
- Stated per application
- Seal type
- DIN 3760 Type A or AS
- Size designation
- Shaft Ø × bore Ø × width
- Medium compatibility
- Air, water, steam, dry heat. Not mineral oil — silicone swells
- Post-cure
- Oven post-cured
- Certifications
- ISO 9001:2015 — certificate 09111526A, valid to 21 February 2027
- Minimum Order
- 10,000 pieces per part number, per compound, or quoted against the part where geometry or tooling makes that unrealistic. Prototype and first-article lots sit outside the minimum.
Dimensional reference
- Shaft diameter
- The first of the three ordering numbers
- Shaft speed
- Surface speed at the lip
- Duty cycle
- Continuous or intermittent — intermittent running extends a silicone lip considerably
- Shaft surface finish
- Matters more here than on any other compound, because the lip has least abrasion resistance to spare
- Peak temperature
- Stated separately from continuous — usually the reason silicone is being considered
Available materials
Rubber Compound Options
Select the compound best suited to your operating environment and application requirements.
| Rank | Compound | Temperature | Why, for a rotary shaft seal |
|---|---|---|---|
| THIS PAGE | Silicone | −60 to +220 °C | The widest range we mix, and the reason to choose it. Low compression set hot, light colours available. Low abrasion resistance — slow shafts only — and it swells in mineral oil |
| Leave silicone if… | the shaft turns at any speed | — | The lip abrades. Specify FKM (−20/+250 °C) — it reaches higher and wears far better — or AEM (−40/+160 °C) at lower cost |
| Leave silicone if… | the medium is mineral oil | — | Specify NBR (−30/+120 °C), the standard oil-seal compound, or FKM above its range |
| Leave silicone if… | the medium is water, steam or brake fluid | — | Specify EPDM (−40/+140 °C) — which is not offered anywhere in this category and should be |
| Available | Neoprene · SBR · natural rubber | See the compound table | Available, but none is a first choice for a rotary lip seal |
Not sure? Send the medium, temperature and load
SERVICE RANGE
−60 to +220°C
the widest we mix
Key advantages
Why Specifiers Choose Margo
280 °C of range
−60 to +220 °C — wider than anything else we mix, and it holds its compression set hot. If your shaft runs beyond what nitrile or FKM can take, this is the compound.
Slow shafts only
Silicone has low abrasion resistance, and a lip seal runs continuously against a moving shaft. Tell us the surface speed before you specify it — on a fast shaft the lip will not last, and we would rather quote you FKM.
Not for mineral oil
Silicone swells in it. Despite the category name, this is not an oil-seal compound — it is a shaft-seal compound for hot air, steam and dry heat. For oil, specify NBR or FKM.
Post-cured, and that is what makes the range real
Silicone is oven post-cured to drive off residual volatiles. Without it the compound does not reach its published temperature or low odour — and it is a step that is easy to skip and invisible on delivery.
Industries served
Global Applications
Heavy Industry
Ovens, dryers, kilns and furnace-adjacent equipment — slow-turning shafts in high ambient heat
Automotive
Exhaust-adjacent and engine-bay heat — not oil-wetted shafts
Pumps & Valves
High-temperature process pumps
Manufacturing process
From Compound to Certification
Material compounding
Polymer blending, additive integration and batch QC in our in-house lab. The silicone grade is set here, and it is chosen for temperature rather than for wear, which the lip has least of.
Mould Design & CNC
Mould design and CNC tool manufacture, in-house, held as a controlled record. Silicone shrinks more than the other compounds, so the tool is cut for it specifically.
Moulding and metal bonding
Elastomer moulded and bonded to the case. Rubber-to-metal bonding in-house.
Oven post-cure
Silicone is post-cured to drive off residual volatiles. Without it the compound does not reach its published temperature performance or low odour. The step that makes the +220 °C real, and the first one a cheap supplier drops.
Quality inspection
Lip concentricity, bore and width checked against DIN 3760, plus hardness and batch sampling.
Export packaging
Industrial packing with documentation. Seals packed to protect the lip — silicone tears more easily than the other compounds, so handling matters more. ISPM-15 treated pallets where timber is used.
Quality assurance
Certified to International Standards
Every product leaves our facility with a documentation package — material test reports, dimensional inspection sheets and a certificate of conformance — giving traceability from raw material to finished part.
ISO 9001:2015 · Certificate 09111526A
Integral Certification Ltd · Valid to 21 February 2027
Scope: rubber moulded components — quality management, not a product approval
IATF 16949 — upgrade in progress, certification targeted by end 2026
ISO 14001 and ISO 45001 — targeted 2027
We do not hold food-contact or pharmaceutical approvals. Tell us which scheme your market requires and we will confirm what we can supply. Seals are made to DIN 3760 and ISO 6194 dimensions. These are dimensional standards, not certifications.
Certification detailProduction metrics
- Since 2005
- In operation
- 60+
- Active clients
- 3–4 weeks from approved sample
- Avg. lead time
Downloads
Technical Documentation
Compound datasheets and dimensioned drawings are issued on request, under NDA where required. Send the shaft speed, the duty cycle and both temperatures, and we will confirm whether silicone suits the application before quoting it.
Request compound guidanceFAQ
Technical & Commercial Questions
Answers to the most common questions from engineering teams and procurement managers worldwide.
What is the minimum order quantity for this part?
We supply in bulk. The minimum run is 10,000 pieces per part number, per compound — and because silicone shrinks differently from nitrile and FKM, it needs its own tool. Prototype and first-article lots sit outside the minimum.
Can you match a competitor specification or reverse-engineer an existing part?
Yes — and if the seal you are replacing is silicone, tell us how long it lasted. A short life on a running shaft usually means the compound was chosen for temperature without checking the speed. We would rather quote you FKM than sell you the same failure twice.
What file formats do you accept for drawings?
PDF, DWG, DXF and STEP — but a drawing is often unnecessary. Shaft diameter, housing bore, width, type A or AS, plus the shaft speed, the duty cycle and both temperatures is a complete specification for this compound.
Do you provide material test reports with each shipment?
Yes. Material test reports, dimensional inspection sheets and a certificate of conformance ship with every consignment. Hardness, tensile to ASTM D412 and compression set to ASTM D395 Method B are tested in-house, and post-cure is recorded on the batch record — it is what makes the temperature rating real. We do not hold food-contact or pharmaceutical approvals.
What are your payment and delivery terms for international orders?
TT and LC accepted, discussed per order. Ex-works Nashik or FOB Nhava Sheva. Commercial invoice, packing list and certificate of origin are issued with every consignment. Seals are packed to protect the sealing lip.
Same compound
Other parts we mould in the same compounds
- Foam Gaskets — Closed-Cell Sponge for Low-Closing-Force Seals · Silicone
- 3 Pin Hole Pad — Three-Way Electrical Pass-Through Grommet · Silicone
- Air Extractor Flap — One-Way Cabin Pressure Relief · Silicone
- Internal Fit Grommets — Single-Bore, Panel-Retained · Silicone
- Glove Box Stopper — Damped Interior Closure Bumper · Silicone
- Compression Pump Inlays — Moulded Elastomer Inserts · Silicone
Guides
Further Reading
FKM vs NBR: Which Rubber Is Right for Your Application?
Compares fluorocarbon and nitrile across temperature, chemical resistance and cost-in-use — FKM −20 to +250 °C, NBR −30 to +120 °C. FKM is the answer where temperature or aggressive media demand it; NBR is the answer everywhere else, and it costs a fraction as much.
Need this part quoted?
Send shaft diameter, housing bore and width — or the old seal. Tell us the shaft speed, the duty cycle and both temperatures. We will confirm whether silicone is the right compound before we quote it, then price against your annual quantity. We respond within 48 hours.